15671-3
DUCTLESS SPLIT SYSTEM HEAT PUMP UNITS
Fans:
a. The unit fan shall be high performance, double inlet, forward curve, direct
drive sirocco fan with a single motor. The fans shall be statically and
dynamically balanced and run on a motor with permanently lubricated
bearings. The indoor fan shall consist of three (3) speeds: Low, Mid, and
Hi and Auto. The fan shall have a selectable Auto fan setting that will
adjust the fan speed based on the difference between controller set-point
and space temperature.
b. There shall be a motorized horizontal vane to automatically direct air flow
in a horizontal and downward direction for uniform air distribution. The
horizontal vane shall significantly decrease downward air resistance for
lower sound levels, and shall close the outlet port when operation is
stopped. There shall also be a set of vertical vanes to provide horizontal
swing airflow movement.
Coil:
The evaporator coil shall be of nonferrous construction with pre-coated
aluminum strake fins on copper tubing. The multi-angled heat exchanger shall
have a modified fin shape that reduces air resistance for a smoother, quieter
airflow. All tube joints shall be brazed with PhosCopper or silver alloy. The
coils shall be pressure tested at the factory. A condensate pan and drain shall
be provided under the coil. A drain pan level switch, designed to connect to the
control board, shall be provided and installed on the condensate pan to prevent
condensate from overflowing.
Controls:
The control system shall consist of a minimum of two (2) microprocessors, one
on each indoor and outdoor unit, interconnected by a single non-polar two-wire
cable. The microprocessor located in the indoor unit shall have the capability
of monitoring return air temperature and indoor coil temperature, receiving and
processing commands from a wireless or wired controller, providing emergency
operation and controlling the outdoor unit. The control signal between the
indoor and outdoor unit shall be pulse signal 24 volts DC. Indoor units shall
have the ability to control supplemental heat via 12 VDC output.
The unit shall have the following functions as a minimum:
a. Automatic restart after power failure at the same operating conditions as
at failure.
b. A timer function to provide a minimum 24-hour timer cycle for system
Auto Start/Stop.
c. Temperature sensing control to enter set points and operating conditions.
d. Automatic air sweep control to provide on or off activation of air sweep
louvers.
e. Dehumidification mode shall provide increased latent removal capability
by modulating system operation and set point temperature.
f. Fan-only operation to provide room air circulation when no cooling is
required.
g. Diagnostics shall provide continuous checks of unit operation and warn of
possible malfunctions. Error messages shall be displayed at the unit.
13089K
